
function roundNumber(num, dec) {
	var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
	
	return result;
}

function sumInputs(className, container, target) {
		inputs = document.getElementsByClassName(className, container);
		var total = 0;
		for(i=0; i<inputs.length; i++) {
				if(inputs[i].value && inputs[i].value >=0){
					total += parseFloat(inputs[i].value);
				}
		}
		target.value = roundNumber(total,2);
		if(target.value=='NaN'){
				target.value="0";
		}
	}

function updateCheckBox(checkbox) {
		if(checkbox && (checkbox.checked==false)) {
			checkbox.checked = true;
		}
}

function updateAge(yearHolder, monthHolder, dayHolder, ageHolder) {
		dtAsOfDate = new Date();
		year = yearHolder.value;
		month = monthHolder.value;
		day = dayHolder.value;
		
		dtBirth = new Date(year, month-1, day, 0, 0, 0);
		
		if ( dtAsOfDate >= dtBirth )
      {

      // get time span between as of time and birth time
      intSpan = ( dtAsOfDate.getUTCHours() * 3600000 +
                  dtAsOfDate.getUTCMinutes() * 60000 +
                  dtAsOfDate.getUTCSeconds() * 1000    ) -
                ( dtBirth.getUTCHours() * 3600000 +
                  dtBirth.getUTCMinutes() * 60000 +
                  dtBirth.getUTCSeconds() * 1000       )

      // start at as of date and look backwards for anniversary 

      // if as of day (date) is after birth day (date) or
      //    as of day (date) is birth day (date) and
      //    as of time is on or after birth time
      if ( dtAsOfDate.getUTCDate() > dtBirth.getUTCDate() ||
           ( dtAsOfDate.getUTCDate() == dtBirth.getUTCDate() && intSpan >= 0 ) )
         {

         // most recent day (date) anniversary is in as of month
         dtAnniversary = 
            new Date( Date.UTC( dtAsOfDate.getUTCFullYear(),
                                dtAsOfDate.getUTCMonth(),
                                dtBirth.getUTCDate(),
                                dtBirth.getUTCHours(),
                                dtBirth.getUTCMinutes(),
                                dtBirth.getUTCSeconds() ) );

         }

      // if as of day (date) is before birth day (date) or
      //    as of day (date) is birth day (date) and
      //    as of time is before birth time
      else
         {

         // most recent day (date) anniversary is in month before as of month
         dtAnniversary = 
            new Date( Date.UTC( dtAsOfDate.getUTCFullYear(),
                                dtAsOfDate.getUTCMonth() - 1,
                                dtBirth.getUTCDate(),
                                dtBirth.getUTCHours(),
                                dtBirth.getUTCMinutes(),
                                dtBirth.getUTCSeconds() ) );

         // get previous month
         intMonths = dtAsOfDate.getUTCMonth() - 1;
         if ( intMonths == -1 )
            intMonths = 11;

         // while month is not what it is supposed to be (it will be higher)
         while ( dtAnniversary.getUTCMonth() != intMonths )

            // move back one day
            dtAnniversary.setUTCDate( dtAnniversary.getUTCDate() - 1 );

         }

      // if anniversary month is on or after birth month
      if ( dtAnniversary.getUTCMonth() >= dtBirth.getUTCMonth() )
         {

         // months elapsed is anniversary month - birth month
         intMonths = dtAnniversary.getUTCMonth() - dtBirth.getUTCMonth();

         // years elapsed is anniversary year - birth year
         intYears = dtAnniversary.getUTCFullYear() - dtBirth.getUTCFullYear();

         }

      // if birth month is after anniversary month
      else
         {

         // months elapsed is months left in birth year + anniversary month
         intMonths = (11 - dtBirth.getUTCMonth()) + dtAnniversary.getUTCMonth() + 1;

         // years elapsed is year before anniversary year - birth year
         intYears = (dtAnniversary.getUTCFullYear() - 1) - dtBirth.getUTCFullYear();

         }
      }
		if(ageHolder){
				ageHolder.value = intYears;
		}
}